Updated to CONTRIBUTING to reflect GitHub, etc.

HOW TO CONTRIBUTE PATCHES TO OpenSSL

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HOW TO CONTRIBUTE TO OpenSSL

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(Please visit https://www.openssl.org/community/getting-started.html for

other ideas about how to contribute.)

Development is coordinated on the openssl-dev mailing list (see the

above link or https://mta.openssl.org for information on subscribing).

If you are unsure as to whether a feature will be useful for the general

OpenSSL community you might want to discuss it on the openssl-dev mailing

list first.  Someone may be already working on the same thing or there

may be a good reason as to why that feature isn't implemented.

Development is done on GitHub, https://github.com/openssl/openssl.

To submit a patch, make a pull request on GitHub.  If you think the patch

could use feedback from the community, please start a thread on openssl-dev

to discuss it.

To request new features or report bugs, please open an issue on GitHub

Having addressed the following items before the PR will help make the

acceptance and review process faster:

To submit a patch, please open a pull request on GitHub.  If you are thinking

of making a large contribution, open an issue for it before starting work,

to get comments from the community.  Someone may be already working on

the same thing or there may be reasons why that feature isn't implemented.

    1. Anything other than trivial contributions will require a contributor

    licensing agreement, giving us permission to use your code. See

    https://www.openssl.org/policies/cla.html for details.

To make it easier to review and accept your pull request, please follow these

guidelines:

    1. Anything other than a trivial contribution requires a Contributor

    License Agreement (CLA), giving us permission to use your code. See

    https://www.openssl.org/policies/cla.html for details.  If your

    contribution is too small to require a CLA, put "CLA: trivial" on a

    line by itself in your commit message body.

    2.  All source files should start with the following text (with

    appropriate comment characters at the start of each line and the

        https://www.openssl.org/source/license.html

    3.  Patches should be as current as possible; expect to have to rebase

    often. We do not accept merge commits; You will be asked to remove

    them before a patch is considered acceptable.

    often. We do not accept merge commits, you will have to remove them

    (usually by rebasing) before it will be acceptable.

    4.  Patches should follow our coding style (see

    https://www.openssl.org/policies/codingstyle.html) and compile without

    warnings. Where gcc or clang is availble you should use the

    https://www.openssl.org/policies/codingstyle.html) and compile

    without warnings. Where gcc or clang is available you should use the

    --strict-warnings Configure option.  OpenSSL compiles on many varied

    platforms: try to ensure you only use portable features.

    Clean builds via Travis and AppVeyor are expected, and done whenever

    a PR is created or updated.

    platforms: try to ensure you only use portable features.  Clean builds

    via Travis and AppVeyor are required, and they are started automatically

    whenever a PR is created or updated.

    5.  When at all possible, patches should include tests. These can

    either be added to an existing test, or completely new.  Please see

    test/README for information on the test framework.

    6.  New features or changed functionality must include

    documentation. Please look at the "pod" files in doc/apps, doc/crypto

    and doc/ssl for examples of our style.

    documentation. Please look at the "pod" files in doc for

    examples of our style.